Antifungal terpenoids from
Neopallasia pectinata
and
in vivo
Zhuo Lan, Zhenyan Bao, Siyao Yi, Lixia Zhu, Yanxin Zhang, Jianchun Qin, Xinyun Cui Abstract
BACKGROUND
Oryza sativa L. (rice) sheath blight, caused by Rhizoctonia solani Kühn, is a major disease threatening rice production. This study identifies antifungal constituents from Neopallasia pectinata (Pall.) Poljakov and characterizes 4‐terpineol against R. solani using in vitro , in vivo , and mechanistic approaches.
RESULTS
Five compounds were isolated from N. pectinata . 4‐Terpineol ( 3 ) inhibited R. solani with an EC 50 of 220.7 μg mL −1 and a minimum inhibitory concentration of 500 μg mL −1 . At 500 μg mL −1 , 4‐terpineol achieved protective and curative efficacies of 42.29% and 55.43%, respectively, in rice plants. Transcriptomic and physiological analyses showed impaired membrane integrity and extensive remodeling of sterol and fatty‐acid metabolism, accompanied by strong Pleiotropic Drug Resistance ( PDR )‐associated responses. 4‐Terpineol also perturbed mitochondrial membrane‐potential homeostasis and induced glutathione‐ and glutathione S‐transferase‐associated responses without detectable reactive oxygen species accumulation under the tested conditions.
CONCLUSION
4‐Terpineol induces membrane‐associated disturbance and extensive adaptive responses in R. solani . Its in planta activity, practical availability from alternative sources, and chemically modifiable structure support its potential as a natural‐product‐derived lead scaffold for further optimization against rice sheath blight. © 2026 Society of Chemical Industry.